Electrode assembly support



Nov. 6, 1962 F. A. ROMANO, JR

ELECTRODE ASSEMBLY SUPPORT Filed Dec. 31, 1959 FIG.3.

INVENTOR: FRANK A. ROMANO,JR. BY;Z fl+/- HI ATTORNEY.

3,0fi2,982 Patented Nov. 6, 19 62 thee 3,062,982 ELECTRQDE ASSEMBLY SUPIURT Frank A. Romano, In, Syracuse, N.Y., assignor to General Electric Company, a corporation of New York Filed Dec. 31, 1959, Ser. No. 863,333 4- Ciairns. (Cl. 313-292) The present invention relates to supports for electrode assemblies such as electron guns of cathode ray tubes and the like, and particularly to supports for such electrode assemblies having substantial mass, such as are frequently found in industrial and military cathode ray tubes.

One problem in the construction of such cathode ray tubes, and particularly those which are intended for operation under rugged environmental conditions such as extremes of acceleration and vibration, is that of providing adequate support for the electron gun portion of the tube within the tube envelope. Especially when such electrode assemblies are relatively massive, which is often the case in multiple beam or high precision tubes for military and industrial applications, the matter of adequately supporting the electron gun against displacement in a direction transverse to the tube neck or electron beam path during shock or vibration becomes particularly vital. Further complicating this problem of support is the fact that the supporting means for the electrode assembly must be capable of being easily inserted within the tube envelope, the interior dimensions of which generally are not precise, and the supporting means must also be capable of withstanding the high temperatures involved in tube manufacture and operation, and capable of accommodating the expansions and contractions involved in excursions to and from such high temperatures.

Accordingly, a principal object of the present invention is to provide improved electrode assembly supporting means for electron guns and the like which insures firm support, particularly against displacements transverse to the axis of the gun, and insures continuous precise positioning of the electrode assembly even under rugged environmental conditions involving large accelerations or I severe vibration.

Another object is to provide an improved support for electron discharge device electrode means, which support is simplified in form, easily and inexpensively manufactured, and readily assembled, and which does not impede insertion of the electrode means into a tube envelope.

Another object is to provide improved centering and support means for an electron gun electrode assembly which is capable of withstanding severe shock and vibration, together with the extreme temperatures encountered in tube manufacture and operation, without permanent deformation or other damage.

These and other objects of the invention will be more fully understood from the following description and the accompanying drawing wherein;

FIGURE 1 is a fragmentary view, partially broken away in axial section, of a'cathode ray tube having electrode assembly supporting means constructed in accordance with the present invention;

FIGURE 2 is an enlarged view of the portion of the structure shown in FIGURE 1 and showing details of the electrode supporting means constructed in accordance with the present invention; and

FIGURE 3 is a view of one form of electrode support constructed according to the invention.

Referring to the drawing, FIGURE 1 shows a portion of a cathode ray tube embodying the present invention and including an envelope 2 having a tubular neck 4 closed at its end by a stem covered by a base 6. Within 20 extending through the base 6' and stem the neck is an electron gun electrode assembly including electron beam forming electrodes 8, 10 and beam deflecting electrodes 12, 14. The various electrodes are positioned and supported relative to one another in any suitable manner, for example by insulating rods 16, 18 to which the electrodes are secured. Suitable potentials for the electrode assembly maybe supplied within the envelope 2 in any suitablemanner, for example by leads portion of the envelope.

At a position adjacent the forward end of the electrode assembly, and at as many other positions along the electrode assembly as may be desired, the electrode assembly is located and supported relative to an envelope hearing surface 22, such as the interior surface of the neck 4, by supporting means to which the present invention is directed. The supporting means at each position includes a plurality of individual supports 30, here shown as circumferentially spaced about the neck axis. The individual supports 30 are secured, as by welds 32, to a suitable bearing member 34 which may be an electrode itself. or an extension from an electrode, as here shown, or an intermediate member to which the electrode assembly is in turn secured.

As best shown in FIGURE 2 each support 30 consists of a metal member including a root portion 38 which is secured, as by welds 32, to the bearing member 34. Extending integrally from the root portion is a set of metal spring fingers 40, 42, here shown as two in number. The first finger 40 of each set extends outwardly and then rearwardly from the root portion 38, and resiliently engages the envelope bearing surface 22 formed by the neck wall so as to support and locate the electrode assembly therefrom. The second finger 42 of each set is also secured to the bearing member 34, preferably being integral with root portion 38 and the first finger 4t), and the distal end portion of the second finger 42 is also disposed for resilient engagement with hearing surface 22, either by direct contact or, as here shown, through finger 40.

The spring constant of the first finger 40, by which is meant the ratio of the spring force exerted by it to its displacement from its rest or neutral position, is made relatively low, so that the first finger 40 provides a relatively soft spring action. This facilitates easy insertion of the electrode assembly into the tube envelope yet insures gentle support and proper location of the electrode assembly within the tube envelope. The second finger 42, however, has a relatively high spring constant, providing a relatively stiff spring action suitable for firmly restraining any movement of the electrode assembly away from its desired location, and limiting to a minimum amount its transverse displacement under conditions of shock and vibration.

Desirably each second finger 42 is so dimensioned and arranged so that it need be deflected only a minimum amount, if at all, during insertion of the electron gun into the tube envelope. Each second finger 42 is also dimensioned, however, so that its distal portion will engage the envelope bearing surface 22, either directly or as shown by pushing against the adjacent portion of the first finger 40, as soon as there is any transverse displacement of the electrode assembly more than a predetermined amount, thus bringing its stiif spring action into play immediately and exerting a strong restraining force against any transverse displacement of the electrode assembly from the centered or other desired position in which it is supported by the several first fingers 40.

Each finger may have any suitable shape, provided each first finger 40 is arranged for resilient contacting engagement with the neck wall or other envelope bearing surface 22 when the electrode assembly is inserted therein, so as to resiliently center and support the electrode assembly with relatively light forces, and provided each second finger 40 is arranged for prompt engagement with an envelope bearing surface for exertion of its relatively large restraining force upon any undesired transverse displacement of the electrode assembly. Preferably each first finger 40 has a U-shape, the inner side 50 of the U extending forwardly from the root portion 38 in a direction generally parallel to the axis of neck 4, and the outer side 52 of the U being longer and extending from the bight 54 of the U rearwardly and gradually outwardly into resilient engagement with the neck wall to its distal end which is spaced rearward of the root portion. This U-shape permits each first finger 4% to cantilever about both the bight portion of the U and the junction of the shorter side 50 of the U with the root portion 38, thereby permitting a larger range of resilient displacement without incurring a permanent set or other damage.

Desirably the portion of each first finger 40 which is intended to contact the neck wall has a slight transverse bow, or embossment 56, so as to be outwardly convex and thereby more nearly complement the cylindrical curvature of the neck wall. Also preferably the distal portion of the second finger 42 is positioned in the path of inward flexure displacement of the corresponding first finger, so that the second finger does not directly contact the neck wall, and hence need not be specially shaped for such contact, but rather exerts its restraining force on the envelope bearing surface 22 only through the first finger.

The material employed for the supports 30 may be any suitable metal which is capable of withstanding the high temperatures involved in tube processing, and which is suitably non-gassy, and preferably non-magnetic. One material which has been found to be satisfactory for the supports is a stainless steel such as the product of International Nickel Company known as Inconel X.

It will be appreciated by those skilled in the art that the invention may be carried out in various ways and may take various forms and embodiments other than those illustrative embodiments heretofore described. It is to be understood that the scope of the invention is not limited by the details of the foregoing description, but will be defined in the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A support for the electrode means of an electron tube, said support being adapted to extend between a first bearing surface associated with the electrode means and a second bearing surface associated with the envelope of the tube and comprising a root portion adapted to be immovably secured to one of said bearing surfaces, a first spring member extending from said root portion for resilient engagement with the other of said bearing surfaces, and a second spring member extending from said root portion for resilient engagement with said other bearing surface, said second spring member being dimensioned and arranged for resilient engagement with said other bearing surface only upon movement of said elec- 4 trode means more than a predetermined amount from the position relative to said envelope at which said electrode means is adapted to be maintained by said first spring member, said second spring member having a larger spring constant than said first spring member.

2. An electrode assembly for an electron tube adapted to be enclosed within the envelope of the tube and comprising a plurality of electrodes secured together, a bearing member associated with said electrodes and forming a first bearing surface, and a plurality of supports adapted to extend between said first bearing surface and second bearing surfaces associated with the envelope of the tube, each said support having a root portion rigidly secured to said first bearing surface, a first spring member extending integrally outward from each root portion for resilient engagement with a second bearing surface, and a second spring member extending integrally outward from each root portion for resilient engagement with a second bearing surface, each said second spring member having a larger spring constant than the corresponding first spring member, and each said second spring member being diinensioned and arranged for resilient engagement with a second bearing surface only upon movement of said electrode means more than a predetermined amount from the position relative to said envelope at which said electrode means is adapted to be maintained by the corrcsponding first spring member.

3. An electrode assembly as defined in claim 2 wherein the distal end of the second. spring member of each support is disposed between said first bearing surface and the first spring member of the respective support and in the path of inward resilient displacement by said envelope of the first spring member of the respective support.

4. A support for a cathode ray tube electron gun comprising a metal strip having a root portion adapted to be rigidly secured to an electrode of said electron gun and having a resilient U-shaped portion, one side of said U- shaped portion being shorter than the other and extending integrally outward from said root portion, the other side of said U-shaped portion being adapted to contact a restraining surface and be resiliently displaced inwardly thereby relative to said root portion during fiexure of said support, and said one side of said U-shaped portion forming a resilient backup portion rigidly secured to and cantilevered from said root portion, the distal end of said backup portion being disposed in the path of inward flexure displacement of said other side of said U-shaped portion, said backup portion being dimensioned and arranged relative to said other side of said U-shaped portion so as to be unflexed until said other side of said U- shaped portion is deflected a predetermined amount, the spring constant of said backup portion being greater than that of said U-shaped portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,323,140 Lane June 29, 1943 2,859,366 Squier Nov. 4, 1958 2,877,370 Hanson Mar. 10, 1959 

